Antigen binding molecules, including antibodies, are used in immunotherapy and solid phase-based applications such as biosensors, affinity chromatography, and immunoassays. These antibodies and antigen binding molecules gain their utility by virtue of their ability to specifically bind their targets.
Linker sequences, which are often peptide-based when employed in biotechnological and biotherapeutic applications, can serve a range of scientifically-relevant applications. For example, a linker can be used as simply a spacer moiety in order to impart a desired structural and/or functional property to a larger molecule. In another example, a linker can impart little or no structural or functional properties to a larger molecule, but can be used simply as a distinguishing feature (e.g., a “marker” or “biomarker” or “tag”), uniquely identifying a larger molecule. In still another example, a linker can be used to impart a recognizable feature that can serve as a binding site for an antibody directed against a larger molecule comprising the linker sequence.
When a linker sequence is used as a distinguishing, detectable or identifiable feature of a larger molecule, an antibody that specifically binds the linker sequence, to the exclusion of other sequences present in the larger molecule, the antibody can serve as a detection agent. Such antibodies can be labeled with a moiety that is detectable under certain conditions. Additional applications for such an antibody include purification and isolation of a molecule comprising the linker, characterization of a molecule in a particular setting, enrichment of the concentration of a population of molecules comprising and/or presenting the linker, and therapeutic applications as well.
In 1993, Whitlow et al. disclosed a synthetic linker peptide comprising the amino acid sequence GSTSGSGKPGSGEGSTKG (SEQ ID NO: 1) (Whitlow et al., (1993) Prot. Eng. 6(8):989-95). The disclosed peptide was studied as a component of an scFv, and was designed to remove a proteolytic site identified in a previous linker peptide. Whitlow et al. concluded that this newly-designed synthetic linker peptide was more stable to proteolysis in vitro when compared to the prior linker peptide upon which its sequence was based, and also showed less aggregation compared to the same prior linker. Whitlow et al. did not disclose any antigen binding molecules directed to their second generation linker peptide.
Disclosed herein are antigen binding molecules, including antibodies, that specifically bind the sequence GSTSGSGKPGSGEGSTKG (SEQ ID NO: 1) and subsequences thereof, particularly GSGKPGSGEG (SEQ ID NO: 2), GKPGSGEG (SEQ ID NO: 3), SGKPGSGE (SEQ ID NO: 499), and/or KPGSG (SEQ ID NO: 500), molecules comprising these sequences and cells presenting such molecules. Humanized forms of the antigen binding molecules are also provided. Applications and uses thereof are also disclosed.